I have the latest version has it been taken out
First of all, you need to be using tabs
Sales Invoices or
Purchase Invoices or both. If you are not using accounts receivable or accounts payable functionality in Manager, then figures on cash-basis or accrual-basis would be the same so the option is not visible on reports as it would be irrelevant.
If you are using invoices, then the option is usually seen in top-right corner when creating a report.